The answer to that question is, like so many things in Roman Catholicism, complicated, and it depends upon whom you ask. That, in turn, depends upon the relative stance of the person you’re talking to with the real teaching of the church. For many years those with a leftward drift tended to discount that kind of fidelity, while those on the other side (like the #straightouttairondale crowd) enthusiastically proclaim it.

A more thoughtful treatment comes from the conservative side of the church with this post, formally entitled Quaeritur: What is the Status of a Catholic Who Dissents from the Magisterium? It comes from the Ite ad Thomam blog, maintained by one Francisco J. Romero Carrasquillo, Ph.D. I hasten to add that my church counts several Carrasquillos (also Puerto Rican) as members; they have not done much for the One Holy Catholic and Apostolic Church, but they have brought honour to the family name, as they are fine Christian people.

He starts to answer this question as follows:

It depends on the level of the Magisterial teaching in question. Some teachings have been defined dogmatically, for example, the Trinity, the divinity of Christ, the virginity of Mary, and many, many others; such that believing in these teachings is part of the definition of what it means to be Catholic. And if someone obstinately denies even the least of these, then they no longer meet the requirements for the definition of what it means to be Catholic. There is no such thing as a Catholic who denies the divinity of Christ—or for that matter a Catholic who denies that the sacramental accidents of the Eucharist continue to exist without a subject in which to inhere.

This is reasonable. Most conservative Christians would say that there is a core of belief which is essential to being a Christian. Where differences arise is in what makes up that core, although again there is a great deal of overlap between what the RCC says is the core and what others do.

Dr. Romero also addresses the issue of whether people who do not are really Catholic; he says they are not. That goes against the idea of some who believe that Roman Catholicism is like flypaper; once it gets on you, you are stuck with it. On one level that makes sense, but it has always struck me as duplicitous that people loudly proclaim to be X while believing things that are flatly contradictory to that proclamation.

But then he goes on as follows:

On the other hand, if someone denies a teaching that is not dogmatically defined, or especially one that is not directly part of the Deposit of Faith, but is simply a theological conclusion or common teaching of the ordinary Magisterium, then this would be different. You wouldn’t cease being Catholic by denying it.

I’m speaking, for example, of the case of a Catholic who for some reason would deny that Our Lady is the Mediatrix of all Graces—a doctrine that hasn’t yet been defined. The same is true of teachings that are logically or theologically derived from defined dogma, but which are themselves not defined.

Many non-Catholics have the idea that being a Roman Catholic is to throw away the brains and accept the teachings of the church without question. That’s simply not the case, if for no other reason than the breadth and complexity of the teaching and the intellectual and historical development behind it is far beyond just about anything else in Christianity. It’s true that many Catholics have never investigated that breadth, and it’s also true that the state of things in most parishes doesn’t encourage that kind of inquiry (which is one reason the RCC bleeds members the way it does.) But it is true that there is a fairly extensive body of belief which the Church has not definitively pronounced on, and in these cases there is room for variance, although Dr. Romero points out that you may be a “bad Catholic” for doing so.

An interesting example comes from Dr. Romero himself: the idea that Our Lady is the Mediatrix of all Graces. It’s safe to say that the #straightouttairondale bunch would proclaim that to be essentially Catholic, but Dr. Romero points out that this has not been raised to dogma by the Church. There are many problems with making that step, not the least of which is that it would make a purely created being the conduit of uncreated grace, something that is avoided in Jesus Christ because he is both God and man united, and thus with an uncreated, divine nature.

So the simple answer to this question is “no.” It depends upon the level a certain dogma holds in the magisterium. Whether that satisfies Protestant concerns is another matter altogether. But we cannot have a discussion on the issue unless we understand where everyone is at, and this should clear up an important point.